Fix bug when unplugging an audio input device whilst using speech input.

media/audio/audio_input_controller.h

Index: media/audio/audio_input_controller.h
diff --git a/media/audio/audio_input_controller.h b/media/audio/audio_input_controller.h
index b21eabadaf2fce91bdfbb5f02a32b54b9a3c4a4a..67c5aa1105c3edbc48e2607f7fee3e576d98b064 100644
--- a/media/audio/audio_input_controller.h
+++ b/media/audio/audio_input_controller.h
@@ -100,6 +100,7 @@ class AudioInputController
   // AudioInputController being created directly.
 #if defined(UNIT_TEST)
   static void set_factory(Factory* factory) { factory_ = factory; }
+  AudioInputStream* stream() { return stream_; }
 #endif
 
   // Starts recording in this audio input stream.
@@ -138,10 +139,18 @@ class AudioInputController
   void DoRecord();
   void DoClose();
   void DoReportError(int code);
+  void DoDataCountCheck();
+
+  void ScheduleDataCountCheck();
 
   EventHandler* handler_;
   AudioInputStream* stream_;
 
+  // Incremented on each call to OnData.
+  int on_data_call_count_;
+  // Only used on the audio controller thread.
+  int previous_on_data_count_;
+
   // |state_| is written on the audio input controller thread and is read on
   // the hardware audio thread. These operations need to be locked. But lock
   // is not required for reading on the audio input controller thread.